Observation of an optical anisotropy in the deep glacial ice at the geographic South Pole using a laser dust logger

We report on a depth-dependent observation of a directional anisotropy in the recorded intensity of backscattered light as measured by an oriented laser dust logger. The measurement was performed in a drill hole at the geographic South Pole about a kilometer away from the IceCube Neutrino Observator...

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Bibliographic Details
Published in:The Cryosphere
Main Authors: Rongen, Martin, Bay, Ryan Carlton, Blot, Summer
Format: Article in Journal/Newspaper
Language:English
Published: Copernicus Publications 2020
Subjects:
Online Access:https://doi.org/10.5194/tc-14-2537-2020
https://noa.gwlb.de/receive/cop_mods_00052384
https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00052037/tc-14-2537-2020.pdf
https://tc.copernicus.org/articles/14/2537/2020/tc-14-2537-2020.pdf
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Summary:We report on a depth-dependent observation of a directional anisotropy in the recorded intensity of backscattered light as measured by an oriented laser dust logger. The measurement was performed in a drill hole at the geographic South Pole about a kilometer away from the IceCube Neutrino Observatory. The drill hole has remained open for access since the SPICEcore collaboration retrieved a 1751 m ice core. We find the anisotropy axis of 126±3∘ as measured below 1100 m to be compatible with the local flow direction. The observation is discussed in comparison to a similar anisotropy observed in data from the IceCube Neutrino Observatory and favors a birefringence-based scenario over previously suggested Mie-scattering-based explanations. In the future, the measurement principle, when combined with a full-chain simulation, may have the potential to provide a continuous record of fabric properties along the entire depth of a drill hole.